Density of neutrophils in lung tissue. In (a) * indicates significant effect of LPS in increasing the PMN cell content in lung tissue (P <0.001). # indicates significant effect of exercise in attenuating the effect of LPS on PMN cell content in lung tissue (P = 0.01). CTR (control): instilled with saline and untrained; Exe (exercise): instilled with saline and trained; LPS: instilled with LPS and untrained; Exe+LPS: instilled with LPS and trained. The microphotograph illustrates the density of neutrophils in the four groups: b = CTR, c = Exe, d = LPS, e = Exe+LPS. LPS, lipopolysaccharide; PMN, polymorphonuclear.